Musical instruments, and in particular percussion and string instruments, require tuning in order to be played properly. Prior art methods of tuning musical instruments require some sort of human intervention. Classically, the piano tuner employs a tuning fork and his own hearing to tune a piano. Likewise, one must rely upon his personal impression of a tone when tuning a string instrument, such as a violin. Tuning gauges for percussion instruments, such as kettledrums, have been developed. These tuning gauges, however, only give an indication of the position of the adjustable tuning member, and not the frequency of the tone produced by the vibrating element or member of the musical instrument.
Not only must percussion and string instruments be tuned before a performance, but sometimes must be returned during the performance. A kettledrum must be tuned during the course of a performance. Typically, kettledrums are arranged in groups of four. Each kettledrum has a different tone range, which overlaps the tone range of its neighbor. Usually, the complete tone range for all four kettledurms is about 1.5 octaves.
Key changes for string instruments, which are made while playing, usually involve changing the effective length of the string by holding it immobile at selected positions. Tuning of a string instrument involves changing the restoring force of the vibrating member. Thus, key changing for stringed instruments is comparatively easy since, effectively, one is changing the boundary value conditions for a one-dimensional harmonic oscillator. Key changes on a kettledrum, however, can only be performed by varying the tension on the drumhead. Thus, a key change operation performed on a kettledrum is identical to a tuning operation on the drum for that key. Key changes for a kettledrum result from changing the coefficient of restoring force of the drumhead. Practically speaking, it is very difficult to change quickly and easily the boundary conditions for a two-dimensional harmonic oscillator, as embodied in a circular drumhead.
During the course of a performance, a kettledrum is played in a number of different keys. Thus, the musician must be able to adjust quickly and easily the tension, and thereby the restoring force, on four drumheads while the performance is being given.
Furthermore, as temperature, humidity and other external conditions change during the performance, the tension on the vibrating element of the musical instrument, whether the instrument is of the string or percussion variety, changes. Thus, the instrument has a tendency to lose its tune during the performance.
The tuning adjustment must also be performed in a darkened, and often noisy, orchestra pit. Nevertheless, it is necessary that the musical instrument be in tune and played in the proper key.
What is needed is a device which can tune a string or percussion instrument to a selected frequency automatically, quickly and accurately. The tuning device must be easy for a musician or non-technical person to operate. The tuning device must also be non-responsive to extraneous sound.